Abstract The reserves and structure of microbial biomass, the number of cultivated micromycetes and bacteria, and the abundance of copies of ribosomal genes of microorganisms in gleyic cryozems and cryoturbated permafrost gleysols (Cryosols) in the vicinity of the village of Dikson were studied. Microbial biomass ranged from 0.0194 to 0.3743 mg/g soil. Fungi predominated in the microbial biomass (62.3 to 98.8%). Fungal biomass ranged from 0.019 to 0.350 mg/g soil, and mycelial length ranged from 8.86 to 435.14 m/g soil. Prokaryotic biomass ranged from 0.0005 to 0.0296 mg/g soil, and abundance ranged from 2.03 × 107 to 1.19 × 109 cells/g soil. The mycelial length of actinomycetes ranged from 0.2 to 15.2 m/g soil. The number of ribosomal genes copies of microorganisms decreased with depth along the soil profiles and ranged: from 4.34 × 107 to 1.49 × 109 gene copies/g of soil for 16S rRNA of archaea; from 8.40 × 108 to 2.31 × 1010 gene copies/g of soil for 16S rRNA of bacteria; and from 7.60 × 105 to 1.00 × 109 gene copies/g of soil for ITS rRNA of fungi. The number of cultivated micromycetes in cultures incubated at +25°C varied from 1.1 × 103 to 9.8 × 103 CFU/g of soil, and at +5°C from 4.7 × 102 to 6.5 × 103 CFU/g of soil. Saprotrophic genera (Penicillium) and genera typical of cold ecosystems (Chrysosporium, Goffeauzyma, Pseudogymnoascus, and Thelebolus) dominated in number and abundance. A decrease was revealed in the number of CFU and taxonomic diversity of microscopic fungi from surface to deeper horizons, regardless of the incubation temperature of cultures. The abundance of culturable saprotrophic bacteria ranged from 229.44 × 103 to 928.66 × 103 CFU/g of soil, with no clear quantitative dependence on the soil profile horizon location. Representatives of the genera Pseudomonas, Bacillus, and Micrococcus dominated, while representatives of the genera Acetobacterium, Arthrobacter, and Acinetobacter demonstrated abundance as subdominant groups. Bacterial strains of the genera Rhodococcus and Sarcina represented minor components. Bacterial strains of the genera Rhodococcus and Sarcina represented minor components. Overall, oligotrophic and psychrotolerant microorganisms, as well as small forms of prokaryotes and fungi, predominated among the culturable microorganisms. All soil biological activity parameters decreased with depth across the soil profiles and from background ecosystems to anthropogenically disturbed ones.

Biological Activity in Soils of Northwestern Taimyr Around the Village of Dikson

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发表日期：

2026年6月22日

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D. A. Nikitin,
E. A. Ivanova,
O. V. Kutovaya,
N. S. Mergelov,
A. V. Dolgikh,
V. K. Kadutskiy,
M. K. Meteleva,
S. Yu. Evgrafova

摘要

Abstract

The reserves and structure of microbial biomass, the number of cultivated micromycetes and bacteria, and the abundance of copies of ribosomal genes of microorganisms in gleyic cryozems and cryoturbated permafrost gleysols (Cryosols) in the vicinity of the village of Dikson were studied. Microbial biomass ranged from 0.0194 to 0.3743 mg/g soil. Fungi predominated in the microbial biomass (62.3 to 98.8%). Fungal biomass ranged from 0.019 to 0.350 mg/g soil, and mycelial length ranged from 8.86 to 435.14 m/g soil. Prokaryotic biomass ranged from 0.0005 to 0.0296 mg/g soil, and abundance ranged from 2.03 × 10⁷ to 1.19 × 10⁹ cells/g soil. The mycelial length of actinomycetes ranged from 0.2 to 15.2 m/g soil. The number of ribosomal genes copies of microorganisms decreased with depth along the soil profiles and ranged: from 4.34 × 10⁷ to 1.49 × 10⁹ gene copies/g of soil for 16S rRNA of archaea; from 8.40 × 10⁸ to 2.31 × 10¹⁰ gene copies/g of soil for 16S rRNA of bacteria; and from 7.60 × 10⁵ to 1.00 × 10⁹ gene copies/g of soil for ITS rRNA of fungi. The number of cultivated micromycetes in cultures incubated at +25°C varied from 1.1 × 10³ to 9.8 × 10³ CFU/g of soil, and at +5°C from 4.7 × 10² to 6.5 × 10³ CFU/g of soil. Saprotrophic genera (Penicillium) and genera typical of cold ecosystems (Chrysosporium, Goffeauzyma, Pseudogymnoascus, and Thelebolus) dominated in number and abundance. A decrease was revealed in the number of CFU and taxonomic diversity of microscopic fungi from surface to deeper horizons, regardless of the incubation temperature of cultures. The abundance of culturable saprotrophic bacteria ranged from 229.44 × 10³ to 928.66 × 10³ CFU/g of soil, with no clear quantitative dependence on the soil profile horizon location. Representatives of the genera Pseudomonas, Bacillus, and Micrococcus dominated, while representatives of the genera Acetobacterium, Arthrobacter, and Acinetobacter demonstrated abundance as subdominant groups. Bacterial strains of the genera Rhodococcus and Sarcina represented minor components. Bacterial strains of the genera Rhodococcus and Sarcina represented minor components. Overall, oligotrophic and psychrotolerant microorganisms, as well as small forms of prokaryotes and fungi, predominated among the culturable microorganisms. All soil biological activity parameters decreased with depth across the soil profiles and from background ecosystems to anthropogenically disturbed ones.